Novel Treatment of Small-Cell Neuroendocrine of the Vagina

Small Cell Neuroendocrine Carcinoma of the Vagina: A Rare Presentation

Primary small cell neuroendocrine carcinoma of the vagina is a very rare disease. We present a case study of a 52-year-old female who presented to the hospital with complaints of urinary dribbling, burning micturition, pain, and per vaginal bleeding for three to four months. A firm globular mass of approximately 5-6 cm was felt in the anterior vaginal wall per speculum examination. Diagnosis of small cell neuroendocrine carcinoma was made with tissue biopsy and immunohistochemistry. Diagnostic imaging (MRI, positron emission tomography (PET)-CT) plays a vital role in reaching the diagnosis and understanding the treatment response. The patient received six cycles of chemotherapy with cisplatin and etoposide and radiotherapy, achieving a complete response, with complete regression of the lesion. The patient had no sign of tumor recurrence and locoregional or distant metastases after six months of follow-up. Nowadays, there is no need for surgery in the treatment of vaginal small cell neuroendocrine carcinoma, rather radiotherapy and chemotherapy are the treatment of choice. We report a case of neuroendocrine cancer of the vagina treated at our institution.

Characterization of giant neuroendocrine cells in the pregnant New Zealand white rabbit vagina demonstrated by histological, histochemical, and immunohistochemical methods

The vagina is part of the genitalia and constitutes part of the birth canal. Sperm is deposited into vagina, and it acts in transport of sperm. Pregnancy is a complex process involving different physiological changes in the body associated with hormonal and metabolic alterations that control maternal and fetal demands. During pregnancy, neuroendocrine cells in rabbit vagina are considered part of the diffuse neuroendocrine system observed throughout the body. Giant neuroendocrine cells in rabbit vagina during pregnancy have not been observed previously. This study detected the presence of giant neuroendocrine cells in the vagina of the pregnant rabbit. The presence of these cells was demonstrated with the use of different histological techniques, including hematoxylin and eosin, PAS, combined Alcian blue-PAS, Crossmon's trichrome, and the Grimelius silver method. Giant neuroendocrine cells were observed in late-pregnancy intraepithelial sites and on the lamina propria. These cells were characterized by vacuolated basophilic cytoplasm with PAS- and PAS-AB-positive granules. Moreover, neuroendocrine cells exhibited an argyrophilic character. Immunohistochemically, neuroendocrine cells in rabbit vagina during pregnancy demonstrated positive immunoreactivity to neuron-specific enolase (NSE) with different intensities, mild immunoreactivity to the vascular endothelial growth factor (VEGF), and negative immunoreactivity to CD68.

Neuroendocrine Neoplasms of the Gynecologic Tract

Simple Summary

Neuroendocrine refers to the cells that synthesize and secrete messenger chemicals such as neuropeptides and amines. Neuroendocrine neoplasms (NENs) are aggressive tumors arising from neuroendocrine cells, with an annual incidence of 6.98/100,000 and a prevalence of 170,000 in the United States. Primary gynecologic NENs constitute ≤2% of female reproductive tumors. NENs of the gynecologic tract are associated with high recurrence rates and dismal prognosis, making their treatment challenging. This article focuses on the updated staging classifications, clinicopathological characteristics, imaging, and management of NENs of the gynecological tract.

Abstract

Gynecological tract neuroendocrine neoplasms (NEN) are rare, aggressive tumors from endocrine cells derived from the neuroectoderm, neural crest, and endoderm. The primary gynecologic NENs constitute 2% of gynecologic malignancies, and the cervix is the most common site of NEN in the gynecologic tract. The updated WHO classification of gynecologic NEN is based on the Ki-67 index, mitotic index, and tumor characteristics such as necrosis, and brings more uniformity in the terminology of NENs like other disease sites. Imaging plays a crucial role in the staging, triaging, restaging, and surveillance of NENs. The expression of the somatostatin receptors on the surface of neuroendocrine cells forms the basis of increasing evaluation with functional imaging modalities using traditional and new tracers, including ⁶⁸Ga-DOTA-Somatostatin Analog-PET/CT. Management of NENs involves a multidisciplinary approach. New targeted therapies could improve the paradigm of care for these rare malignancies. This article focuses on the updated staging classifications, clinicopathological characteristics, imaging, and management of gynecologic NENs of the cervix, ovary, endometrium, vagina, and vulva, emphasizing the relatively common cervical neuroendocrine carcinomas among these entities.

Emerging Therapeutic Concepts and Latest Diagnostic Advancements Regarding Neuroendocrine Tumors of the Gynecologic Tract

Neuroendocrine neoplasms (NENs) are particularly rare in all sites of the gynecological tract and include a variety of neoplasms with variable prognosis, dependent on histologic subtype and site of origin. Following the expert consensus proposal of the International Agency for Research on Cancer (IARC), the approach in the latest World Health Organization (WHO) Classification System of the Female Genital Tumours is to use the same terminology for NENs at all body sites. The main concept of this novel classification framework is to align it to all other body sites and make a clear distinction between well-differentiated neuroendocrine tumors (NETs) and poorly differentiated neuroendocrine carcinomas (NECs). The previous WHO Classification System of the Female Genital Tumours featured more or less the same principle, but used the terms ‘low-grade neuroendocrine tumor’ and ‘high-grade neuroendocrine carcinoma’. Regardless of the terminology used, each of these two main categories include two distinct morphological subtypes: NETs are represented by typical and atypical carcinoid and NEC are represented by small cell neuroendocrine carcinoma (SCNEC) and large cell neuroendocrine carcinoma (LCNEC). High-grade NECs, especially small cell neuroendocrine carcinoma tends to be more frequent in the uterine cervix, followed by the endometrium, while low-grade NETs usually occur in the ovary. NENs of the vulva, vagina and fallopian tube are exceptionally rare, with scattered case reports in the scientific literature.